Regardless of whether the scale of a communication network is large or small, demand for enlargement of capacity of communication between nodes, which are components of a network, has been growing more and more. For meeting the above demand, some techniques for eliminating various bottlenecks relating to optical interconnections have been developed.
For example, Non-patent Literature 1 discloses a technique that realizes error-free operation of 25 Gbps/ch over a multimode fiber having a length of 300 meters, by use of a silicon-photonics-based optical transceiver.
According to the technique disclosed in Non-patent Literature 1, optical interconnection of 25 Gbps/ch via an optical fiber requires electric power consumption of approximately 5 mW/Gbps. This value does not include electric power consumption of a laser diode which is a light source. When the electric power consumption of the laser diode is taken into consideration, further electric power consumption is required for realizing the system disclosed in Non-patent Literature 1. Further, in the case that N nodes are connected in a full mesh manner by use of the above optical transceiver, 2N*(N−1) optical fibers are required. Thus, in the case that N is large, the network system becomes large.